Brown the butter! Melt butter in a large saucepan over medium heat. As it begins melting, continue stirring until it becomes bubbly and foamy!

Butter changes color from pale yellow to a deeper tan color the longer it cooks.  You'll also begin to smell a nutty aroma.  Once it's darkened, turn heat off.

Add in marshmallows and vanilla and stir until melted.

Add Lucky Charms cereal to melted marshmallow mixture.  Stir until combined.

Pour cereal mixture into an 8x8 greased or parchment lined baking pan.  Using a silicone spatula, pat mixture down into pan, making sure to fill in the corners and edges of the pan.  Tip: I like to wet my spatula with water to keep the cereal treats from sticking to my spatula as I press them down into the pan.

Allow treats to set up for about an hour.  Once firm, pull parchment from pan and cut into desired size squares.  For ultimate freshness, store in an airtight container at room temperature.